This invention relates generally to chassis mounted electronic modules, and more particularly to a mechanism for positively inserting and retracting such modules.
The use of electronic modules in electronic equipment is well-known and ever-growing. As it continues to grow, greater densities of modules in a given piece of equipment become necessary. This is especially true in compact systems such as those used on aircraft and space vehicles.
Most electronic modules, such as those which contain printed circuit boards, microprocessors, substrates, etc., have some kind of pin contacts disposed along their edges for mating with contacts mounted on the equipment main chassis. In order to assure good electrical contact the mating tolerances must be extremely close. Thus, there are often very high friction forces to be overcome when installing or removing a module. In dense configurations it is often impossible to apply sufficient manual force to insert or retract the module assemblies.
Also, the pin and mating contacts must often be blind-mated in very dense arrangements of such modules. Therefore it is necessary that the module be properly aligned during insertion or retraction, otherwise the pin contacts could be bent or broken.
Wedge-lock mechanisms are currently employed on electronic module assemblies to provide a positive tie-down when the assemblies are inserted into the mating assemblies in the main chassis. The wedging action provides good thermal interface for the module assemblies which are usually in-line cooled. While the wedge-lock mechanism is a good locking device, there are some shortfalls in present devices.
For example, there is no mechanical advantage for the engagement of units where insertion forces are required beyond those achievable by manual operations. In devices which have some means for mechanical advantage a separate tool is usually required for operation. Most of the devices have no integral extracting capability. Consequently, separate extracting provisions must be made and these provisions are made at the expense of critical volume limitations.